The Nationals have promoted top prospect Lucas Giolito to Class AA Harrisburg, deeming the 21-year-old right-hander ready to start pitching at the upper levels of their farm system.

Giolito, recently named the No. 1 prospect in baseball by MLB.com, went 3-5 with a 2.71 ERA in 13 games (11 starts) for Class A Potomac over the season’s first half, striking out 86 batters in 69 2/3 innings.

He also earned the starting assignment for the All-Star Futures Game two weeks ago in Cincinnati, tossing two scoreless innings for Team USA.

The Nationals’ first-round pick in the 2012 draft (16th overall), Giolito was selected despite knowledge of a potentially serious elbow injury. He had Tommy John surgery later that summer to repair a torn ulnar collateral ligament and missed most of 2013 but has come back since healthy and dominant.

In 45 total minor-league games (43 starts), Giolito is 15-8 with a 2.38 ERA, striking out 236 batters over 206 1/3 innings.

Though the Nationals are being somewhat aggressive in promoting Giolito to Class AA at this stage of his professional career, they’re still monitoring his workload closely. As they do with every young pitcher in the organization, even more so those who had major arm surgeries, the Nationals are limiting Giolito’s innings count.

After totaling 98 innings last season at low-Class A Hagerstown, he is expected to be held to roughly 120-to-130 innings this season, then be held to roughly 150-to-160 innings next season, even if he reaches the majors.

Mike Rizzo is wading through the offseason with two separate to-do lists. One covers everything Bryce Harper and the other three distinct gaps in his roster: catcher, second base and the third spot in the starting rotation.

The Harper list will ultimately be decided by ownership. Rizzo wants him back. It’s up to the Lerner family how much they are willing to spend on a return. They were the decision-makers on Max Scherzer’s contract. They will again be so with Harper, weighing many of the same things he will, such as legacy, winning and off-the-field futures.

The other list is more mundane. However, it may be more important. The Nationals have multiple quality solutions if Harper signs elsewhere. And no matter where he ends up, they needed to work on the secondary list. Monday, the Nationals reportedly agreed to a two-year deal with catcher Kurt Suzuki, making headway there. So, let’s first take a look at second base before checking on the third rotation spot later in the week:

The in-house option: Split time between Wilmer Difo and Howie Kendrick

Rizzo told reporters at the general manager meetings he felt good about using the above combination to take care of second base next season. Kendrick would, theoretically, provide a steady bat. Difo would, theoretically, provide athleticism the lineup needs and solid defense at a spot where it did not exist the last three seasons with Daniel Murphy.

The platoon line appears clean: Kendrick would be a right-handed option, Difo, though a switch-hitter, a left-handed choice since he is better against right-handed pitching. Difo could also carry more of the load early in the season assuming the Nationals slow play Kendrick in his age-36 season when coming back from an Achilles tendon tear. Nationals medical staff informed Kendrick he would be “back to normal” if he followed the post-surgery protocols.

“And that’s very refreshing to hear something like that, especially if you have an injury of this caliber,” Kendrick told me in September. “Years ago, it might not have been the same. But now with the advancement of technology and the way they do surgery I feel really confident I’ll be back to normal and playing. Just the process, I’ve got to stick with the process and trust it. “Mentally, I really don’t have a problem with it. I know it just takes time because I’ve had injuries before. So, it’s like, all right, just follow the protocol and I’ll be where I need to be when it’s time.”

Kendrick is doing most of his rehabilitation work at Banner Health in Tempe, Arizona. The facility is just down the road from his house. It also allows him to work with physical therapist Keith Kocher, who Kendrick knows from his time with the Los Angeles Angels. Kocher also knows Nationals director of athletic training Paul Lessard and athletic trainer Greg Barajas. Barajas previously worked for Kocher.

Difo, entering his age-27 season, is nearing the end of the line with the organization. He had just a .649 OPS last season in 408 at-bats. There’s little to indicate an offensive uptick is forthcoming. Both he and Kendrick, who will become a free agent, are likely gone after this season.

Should the Nationals choose this platoon path, they would have to live with Difo’s lack of offense and occasional in-field brain freezes. Davey Martinez likes to hit him ninth when he plays, bumping the pitcher in front of him. He would like Difo to calm his swing and have a more measured approach at the plate.

Relying on Kendrick following the injury is a gamble. But, this pair is an option if the organization believes everything else is in place. A team .723 OPS at the position would qualify for middle of the National League pack last season. Kendrick and Difo combine for a .703 career OPS.

The free agent choices: Old, but reliable

Two of the six Gold Glove finalists at second base in 2018 are on the market. Jed Lowrie, who reinvented his offensive effectiveness during the last two seasons, and DJ LeMahieu, who won his third Gold Glove this year.

LeMahieu is the top option for the Nationals if they want to make a hefty investment. He’s 30 years old, a two-time All-Star, the league’s best defender at the position and the 2016 National League batting champion (hello, Coors Field: .391 at home and .303 on the road that season).

What’s interesting is his career OPS-plus, which is adjusted for a hitter’s park, is well below that of Kendrick. Kendrick has a 107 career OPS-plus, LeMahieu 92. And Kendrick didn’t earn the gap only earlier in his career. He put together a 118 OPS-plus in 2017 when being used properly by both the Phillies and Nationals in a reduced role. However, LeMahieu would be a significant fielding upgrade for a team that needs to be better at cutting 90 feet here, 90 feet there from the opposition.

Lowrie is going into his age-35 season. He delivered two of the top seasons of his career in the last two years. Both earned a 120 OPS-plus. He’s shown more power and more patience at the plate. The question is how much to pay him for those last two seasons, the usual paying-for-past-performance risk. The significant dips in Lowrie’s average and slugging percentage following the All-Star break last season can be viewed as red flags.

Asdrubal Cabrera, Ian Kinsler, Brian Dozier and Murphy are also among the lot available. None are getting younger.

The trade options: Limited.

To reiterate: Limited. First, the Nationals’ assets have dwindled in recent years. Second, Carter Kieboom could be ready to play second in 2019 if he is still in the organization. Third, there’s no reason to burn an asset to fill this spot now.

A recommended path

Signing Suzuki will help patch catcher. Another move is likely coming there. Perhaps a second low-cost veteran. Remember, the Nationals allotted roughly $11 million to the position last season. Suzuki will cost half that, which leaves room for further investment without increasing the year-over-year payroll in regards to the Competitive Balance Tax. The salary cost stays the same, the tax threshold rises, you find savings at that spot.

Resolving the catcher position, at least in part, delivers second base as one of the few remaining uncertain spots on the roster. Which in turn provides the Nationals wiggle room when making a decision this offseason. So, the recommendation is to stick and wait. Shoring up this spot could be a move for July or even August at a much lower cost. In the interim, the Difo-Kendrick platoon is surrounded by enough current talent to hover near league average without being a significant hole.

The Nationals took a step Monday morning toward fixing one of their largest ailments.

They signed veteran catcher Kurt Suzuki to a two-year deal, according to multiple reports. Suzuki gives the Nationals at least a partial solution to a spot which spent most of the season as a distinct problem. Nationals catchers finished 14th in the National League in OPS last season.

The question around Suzuki is not if he will be an improvement -- it’s hard not to be -- but if this signals the Nationals have again given up on trying to acquire Miami catcher J.T. Realmuto. Everything indicates the Marlins’ asking price to be extremely high, think Juan Soto or Victor Robles to start, and this signing ostensibly withdraws the Nationals from the Realmuto chase.

Washington could pair Suzuki with an in-house defensive option like Spencer Kieboom. The problem with that approach is the likelihood of injury. Suzuki is a 35-year-old catcher enter his 13th season. Even if he’s not injured, he’s unlikely to play more than 90 games. If he is injured, that leaves the Nationals with the same troubling situation of last season when Kieboom and Pedro Severino were splitting time when Matt Wieters was out.

At the least, Suzuki will be an improvement. His 2.1 WAR from last season severely outpaces the -0.1 WAR compiled in 2018 by Kieboom, Wieters and Severino. Though, he is not the “front-line catcher” Rizzo said at the general manager meetings the team would pursue.

Another thing to note here: It’s just Nov. 19 and Rizzo has done a lot of chipping away at the Nationals’ problems without spending big money. Reliever Kyle Barraclough was acquired for international slot money the team was unlikely to use anyway. Reliever Trevor Rosenthal is on an incentive-laden deal to likely be the setup man with a baseline price lower than that of Ryan Madson last season. And Suzuki’s last deal was for one year and $3.5 million. Expect this deal to be in that neighborhood. That’s significant filler early and at a low cost.